Bumper construction for loom pickers



Dec. 5, 1950 w. D. DODENHOFF 2,532,543

BUMPER CONSTRUCTION FOR LOOM PICKERS Filed Sept. 20, 1948 gz um 17. fiodezzlzgf Berk FZZys Patented Dec. 5, 1950 UNITED STATES PATENT OFFICE BUMPER CONSTRUCTION FOB LOOM PICKERS The present invention relates to an improved form bumper construction and more particularly to an improved form bumper construction adaptable for use in checking the movement of the picker of a box-type loom.

In a box-type loom, a picker is positioned on either end of the lay of the loom, each picker being guided for reciprocating horizontal movement upon a horizontal picker shaft mounted in suitable brackets secured to the lay of the loom. The movement of the picker upon its shaft is determined by the movements of a picker stick linked by suitable means to the main power source driving the loom. The picker is reciprocated upon its shaft by the picker stick to accelerate and decelerate the shuttle at very high cyclic rates approaching 180 or more cycles per minute. During the forward stroke of this cycle upon apropriate movement of the picker stick, the picker accelerates to throw the shuttle at a very high velocity through the warp shed to the other side of the 100m, where a similar picker catches the shuttle and decelerates the shuttle, preliminary to throwing the shuttle back across the loom. Thus it can be seen that the acceleration and deceleration forces exerted by and upon the picker and picker stick when operating at such high cyclic rates are of considerable magnitude and some means must be provided for checking the movements of the picker, particularly at the end of its forward, accelerating movement.

The checking of the forward, accelerating movement of the picker has been heretofore accomplished by means of a form bumper mounted upon the picker shaft and positioned to intercept the path of the picker near the termination of its forward movement. The usual form bumper comprises an elongated strap having circular apertures formed at either extremity thereof adapted to receive the picker shaft therethrough. The strap is deformed or bent to align such apertures so that the picker shaft may pass therethrough. The central portion of the strap is then deformed outwardly from the picker shaft and is flexed with substantial frictional resistance when struck by the picker.

The form bumper of the present invention comprises a primary or outer flexing strap and a secondary or inner flexing strap secured together by suitable means, as by riveting. Bumper seats or blocks are provided adjacent each extreme end of the strap and the extremities of the strap and the seats or blocks are apertured to receive the picker shaft there/through.

In the present invention, the primary flexing strap is an elongated, generally rectangular member formed of a plurality of strips of fabric impregnated with rubber and bonded together to form a unitary, laminated structure. The inner flexing strap, the intermediate flexing strap and the seats or blocks of the form bumper of the present invention are formed of leather. The primary flexing member must be able to withstand the flexing stresses set up by the high cyclic rate impacts on the picker during the continuous operation of the loom. I have found that the employment of a laminated fabric and rubber primary flexing member results in a material increase in the life of the complete form bumper construction. The flex life of the laminated primary flexing member is several times that of a similar member made of leather and the useful life of the form bumper is further improved by providing relatively large apertures at either extreme end of the 'primary flexing member so that there is no contact between the picker shaft and this member during the movement of the form bumper upon the shaft.

It is, therefore, an important object of the present invention to provide an improved form bumper construction capable of withstanding the extreme flexing stresses encountered upon checking the movement of a picker in a box loom.

Another object of the present invention is to provide a form bumper in which the primary flexing member is a laminated strap formed of rubber impregnated fabric laminae bounded into a unitary structure.

It is a further important object of this invention to provide a form bumper in which the primary flexing member is a fabric-rubber laminated strap provided with enlarged apertures at its extreme ends to prevent contact between the picker shaft and the primary flexing member.

Other and further objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

On the drawings:

Figure 1 is a fragmentary perspectiveview of a portion of a box-type loom illustrating a picker shaft having mounted thereon a picker and. a form bumper of the present invention; and

Figure 2 is a sectional View, with parts shown in elevation, of a form bumper of the present invention in its non-flexed position.

As shown on the drawings:

In Fig. 1, reference numeral Ill refers to a picker shaft supported upon the lay of a loom (not shown) by means of brackets H having an upper cylindrical portion l2 axially apertured as at l3 to receive the shaft l therethrough. Shaft I0 carries a picker [4 slidably mounted thereon, the picker [4 comprising a generally cylindrical portion l5 axially apertured as at It to receive the shaft l0 therethrough. The aperture is is of slightly larger diameter than the shaft H) so that the picker is slidably supported thereon. A

e o Cylindrical portion 17 is f0 'med integrally extending completely through the seat blocks 32,

with the portion l5 of the picker M and is supported in spaced relation thereto by an integral arm IS. The axis of the portion l! is parallel to and spaced from the axis of the cylindrical portion I 5 of the picker [4.

A pair of parallel guiding ways ii! are provided in spaced relation on either side of the arm 18 and serve to guide the picker l5 in its reciprocating motion upon the picker shaft ll].

A picker stick 26 is mounted on the lay by any conventional linkage (not shown) and is adapted for movement in a plane parallel to the axis of the shaft I6. The upper portion of the picker stick 20 extends through an elongated, generally rectangular aperture 2| formed in the arm I8 of the picker l4 and in the adjacent portion of the cylindrical housing 15. The picker M is thus adapted for relative movement along the shaft l6 upon appropriate movement of the picker stick 2B, the movement of the picker it being further guided by means of the Ways H. The portion I! of the picker M is provided in either of its circular faces with a generally conical recess 22 adapted to receive one extremity -23 of the shuttle 24.

At the start of the accelerating motion of the picker 1 4. the conical end portion 23 of the shuttle 24 is seated in the recess 22 formed in the forward face of the picker portion [1. Upon movement of the picker stick 2! the picker 14 is moved axially along the shaft ill at a rapidly accelerating rate. After the shuttle 24 is thrown, the forward motion of the picker is checked by means of a form bumper 26 mounted upon the picker shaft l9 directly in the path of the picker during its forward movement along the shaft.

In Figs. 1 and 2, the form bumper 26 is shown as comprising a primary or outer flexing member 21 of elongated, generally rectangular configuration. A secondary or inner flexing strap 28 is secured to the primary flexing strap by means of rivets or other suitable fastening means 29. The secondary flexing member 28 is also generally rectangular in configuration and is somewhat longer than the primary flexing strap 21. The ends of the primary and secondary flexing straps are in extended surface engagement and are secured together by rivets 33 so that the secondary strap 28 is flexed with its central por tion spaced from the primary flexing strap 21 as illustrated in Fig. 2. An intermediate flexing member 38] is provided between the primary and secondary flexing straps 21 and 28 respectively and is secured to the secondary strap 28 by rivets or other suitable fastening means 3!. The intermediate member thus fits between the primary and secondary flexing straps and is in extended surface engagement with the interior face of the secondary strap 28.

A p uralit of smaller rectangular members or seats 32 are secured to the outer faces of the both primary and secondary flexing members 21 and 28 adjacent their extreme ends. The seating members are in engagement with orresp nding faces of the primary and secondary flexing mem- 4 bers and are secured thereto by means of rivets 33 or other suitable fastening means. The blocks 32 provide additional thicknesses of material adjacent the ends of the flexing members and serve to reinforce the structure at this point without interfering with the flexibilit of the form bumper as a whole.

As shown in Fig. 2, the entire assembly 25 is apertured adjacent each end with the apertures the primary flexing member 2'! and the secondary flexing member 28. The seating blocks 32 are apertured as at 34 to receive the shaft ill, the size of the apertures 34 corresponding generally to that of the shaft 10. The secondary flexing member 28 is apertured as at 36, the size of the aperture 36 being identical with that of the apertures 34 of the blocks 32. The primary flexing member 21 is apertured as at 31, the aperture 3! being substantially larger in diameter than the apertures .34 and 35 in the blocks 32 and the secondary flexing member 28, respectively.

As shown in Fig. l, the form bumper is mounted on the shaft by flexing both the primary strap 21 and the secondary strap 28 so that the shaft [0 may be passed through the apertures 34, .35 and 37. The central portions of the straps 2'! and 28 are thus bowed away from the shaft It to define an inverted, generally U-shaped assembly.

The secondary flexing member 28, the inte mediate flexing member 36 and the seating blocks 32 are each formed of leather sufficiently cured to be resilient but not overly flexible. In the form bumpers of the prior art, the primary flexing strap 2! has also been formed of leather identical to that of the members 28, 30 and 32. In the form bumper of the present invention, however, the primary flexing member is an integral laminated structure formed of superimposed laminae of impregnated fabric and rubber. Both the rubber and the fabric are flexible, the flexibility of the laminated structure depending upon the specific formulation of rubber employed and the degree of vulcanization er curing of the rubber. As illustrated in Fig. 2, the strap 21 comprises a plurality of layers 35 of rubber impregnated fabric superimposed and bonded together by a rubber composition 39 extending through the fabric layers 38 and present on each side surface thereof to form an integral laminated structure. It will of course be realized that the number of laminae .present :in the member 2! will depend upon the flexibility desired in the member and the specific conditions under which the form bumper of the present invention is employed. Also the term rubber as used herein in lu within its scope natural rubber and synthetic rubbers, such as Buna N, G R S and the like.

The advantages residing in the form bumper of the present invention will be readily appreciated by those skilled in the art from the following explanation. I have found that the flexing member 2! formed of rubber impregnated fabric is capable of withstanding a great number of applications and release of flexing stress caused by movement of the picker Hi upon the picker shaft ID. Not only is the form bumper of the present invention more resistant to such flexing stresses, but also the stress necessary to deform the form bumper may be varied by varying the composition, the curing or the number .of laminations of the member 21. Further, sliding friction between the member 21 and the rod In by contact of the margins of the aperture in the member 21 receiving the rod with the rod is eliminated by the provision of the enlarged apertures 31 at the extremities of the member. Any sliding contact between the form bumper and the shaft is obtained between the marginal edges of the apertures 34% and 3t and the shaft so that any wear which occurs will take place in either the secondary flexing strap 28 or the seats or blocks 32 rather than in the primary flexing member 27. The secondary straps, being of leather, are substantially more wear resistant to such sliding contact than the primary strap 21.

In operation, the form bumper abuts that bracket arm H most remote from the picker I4 and the picker stick 26. The picker stick at the end of its forward stroke contacts the face of the nearest outer seat 32 so that these members suffer any frictional abrasion which may occur upon the repeated striking of the form bumper by the picker Id or by the abutment of the form bumper 26 with the bracket arm H. The primary flexing member 27 is thus protected from abrasive action from either the bracket arm or the picker.

I have found, in actual commercial practice in box-type looms, that the primary flexing strap 27 far outlasts the leather seats which are brought into contact with either the picker or the bracket arm i I The extreme flexing stresses imparted to the primary flexing member are readily accommodated by this member for a period of time far in excess of the useful life of the leather primary flexing straps formerly employed in form bumpers of this type. This unexpected and unobvious increase in the life of the form bumper of the present invention is attributed to the provision of the rubber-fabric laminated member 2'! and the provision of the enlarged apertures 31.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise that necessitated by the scope of the appended claims.

I claim as my invention:

1. A form bumper adapted to be mounted on a picker shaft of a box-type loom to check the movement of a picker guided by the shaft, com.- prising a primary flexing strap formed of a plurality of rubber impregnated fabric laminae bonded into an integral structure and having apertures formed at its ends to freely receive said shaft therethrough, and a secondary flexing strap formed of leather secured to said primary member and having apertures formed at its ends to receive said shaft therethrough in tight gripping engagement, said secondary flexing strap serving to mount said primary flexing member on said shaft in a U-shaped configuration while maintaining said primary member out of abrasive engagement with said shaft, said flexing straps being capable of flexing movement when struck by said picker to check the movement of the picker along the shaft.

2. A form bumper adapted to be mounted on the picker shaft of a box-type loom to check movement of a picker guided by said. shaft, comprising a primary flexing member formed of a plurality of rubber impregnated fabric laminae bonded into an integral structure and having apertures formed at its ends to freely receive said shaft therethrough when deformed into a U-shaped configuration, and a secondary flexing strap formed of leather secured to said primary member and having apertures formed at its ends in registry with the apertures of said primary member and slidably receiving said shaft therethrough, said members being mounted on said shaft with their central portions bowed away from said shaft and being capable of flexing movement when struck by said picker to check the movement of the picker along the shaft, end portions of said primary member being maintained out of abrasive contact with said shaft by said secondary strap.

3. In a form bumper adapted to be mounted on a picker shaft of a box-type loom to check movement of a picker guided by said shaft, a primary flexing member mounted on said shaft and formed of a plurality of rubber impregnated fabric laminae bonded into an integral structure, said member having enlarged apertures adjacent opposed ends thereof for receiving said shaft therethrough, and means for retaining said flexing member on said shaft without abrasive contact therebetween, said flexing strap being capable of flexing movement to check the movement of said picker along said shaft.

4. In a form bumper adapted to be mounted on a picker shaft of a box-type loom to check the movement of a picker guided by said shaft, a primary flexing strap formed of a plurality of rubber impregnated fabric laminae bonded into an integral structure and apertured at its ends to freely receive said shaft when deformed into a U-shaped configuration, said flexing strap being capable of flexing movement to check the movement of said picker along said shaft, and means for retaining said strap on said shaft for flexing movement without abrasive contact between said strap and said shaft.

5. In a form bumper adapted to be mounted on a picker shaft of a box-type loom to check the movement of a picker guided by said shaft, a primary flexing member formed of a plurality of rubber impregnated fabric laminae bonded into an integral structure and having apertures formed at itsends to freely receive said shaft therethrough, and a secondary flexing member formed of leather and secured to said primary flexing strap and having apertures formed at its ends to receive said shaft therethrough in tight gripping engagement when deformed into a U- shaped configuration, said secondary flexing member serving to maintain the form bumper in position upon said shaft in the path of said picker to check the movement of the picker along the shaft by flexing movement. 7

WILLIAM D. DODENI-IOFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

